Mammographic Density and Columnar Cell Lesions of the Breast

Background

Columnar cell lesions, or CCLs, are common non-cancerous changes to the cellular structure of the breast. CCLs were first identified over 100 years ago, and have become increasingly common in mammograms during the last five years. However it is not yet known how they are related to breast cancer.

CCLs may be related to mammographic density, or MD, which refers to the appearance of the breast tissue during a mammogram. MD varies within and between individuals and is related to the amount of collagen, fat and other tissue types within the breast. MD is a significant risk factor for breast cancer, for reasons that are not well understood.

Do some CCLs progress over time and develop into early types of breast cancer? If so, how can we distinguish those CCLs that are likely to progress (and will require surgical removal) from those that are less likely to become cancerous (and will require careful monitoring rather than potentially unnecessary surgery)?

Aims and Relevance

We plan to answer these questions by comparing genetic mutations in CCLs and cancerous lesions found in the same breast. This analysis will identify CCLs that progressed into breast cancer, and also specific gene mutations that may be involved in tumour development.

We also aim to determine whether CCLs from denser breast tissue contain more mutations and are at higher risk of developing into breast cancer. We also hope to identify specific genetic mutations that are associated with denser breast tissue.

The ultimate aim is to help physicians decide how best to treat the increasing number of women who present with CCLs and/or high MD. In addition, identifying specific gene mutations associated with CCLs will provide valuable information about the earliest stages of breast cancer, and may eventually result in the introduction of new therapies.

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